While the redbay ambrosia beetle has been targeted as the No. 1 threat to South Florida’s avocado industry, a new study led by UF/IFAS researchers are finding the need to spread the focus onto other beetles that can carry the deadly laurel wilt pathogen.

To find out just how many species of ambrosia beetle transmit the fungus that causes laurel wilt (Raffaelea lauricola), Randy Ploetz, UF/IFAS Plant Pathology Professor based at the Tropical Research and Education Center (TREC) in Homestead, and his colleagues collected hundreds of beetles. They put them through a lab procedure to grow the laurel wilt pathogen. The test showed scientists how many spores of the fungus were in each beetle.

“Several beetles other than redbay ambrosia beetle carry the pathogen,” Ploetz said. “However, it will be important to determine their roles in the spread of this disease. But the results suggest that focusing on the redbay ambrosia beetle regarding the avocado situation may not be a good idea.”

Daniel Carrillo, an Entomology Assistant Professor at the TREC, found more than 14 different ambrosia beetles may infest avocado trees. He is currently studying each to identify key players in the spread of this disease and working on ways to control them.

According to Jonathan Crane, a Tropical Fruit Extension Specialist at the TREC, avocado producers have known for some time that other ambrosia beetle species besides the redbay are transmitting the pathogen to avocado in their groves. Since the research focus changed, Crane stresses the importance of growers and researchers partnering to find better management strategies for all laurel wilt-transmitting beetles. “Knowing laurel wilt’s other vectors changes things, and knowing it has potentially multiple vectors adds additional concern for producers,” Crane said.

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